This invention pertains to electrical equipment housings or "racks" for receiving slidably mounted electrical equipment units and, more particularly, to a cable management arm and flexible linkage assembly for use in such racks.
It is well known to mount one or more electrical equipment units, each contained in its own housing, in a larger housing called a "rack." The rack is usually vertically oriented so that one equipment unit is mounted above or below another equipment unit. Each equipment unit may be rigidly mounted in the rack, or it may be slidably attached to the rack through the use of well known drawer slides, which permit each equipment unit to slide (within the limits of the drawer slides) out of the front or the back of the rack to facilitate installation, removal, servicing and adjustment of the equipment unit. Electrical or optical cables are used to interconnect one equipment unit to another and are usually routed along the back of the rack, which may be uncovered or accessible through a door that is hinged to the back of the rack.
Because of the sheer number of cables that may be located in the back of the rack, problems are frequently encountered when attempting to service, adjust or remove an existing equipment unit in the rack, or to install a new equipment unit in the rack. The severity of the problem increases when drawer slides are used, and the problem can become particularly acute when very deep (distance from front to back) equipment units are mounted in the rack, because deeper units require more travel when sliding the unit in or out of the rack. Adding to this problem are the cables themselves, which may be thick and stiff and, consequently, not easily bendable in the limited space found at the back of the rack. Furthermore, some cables, such as fiber optic cables, require minimum bend radii to insure that there is no breakage of the glass fibers in the optical cables.
Accordingly, the invention described below is a rack and cable management assembly that can manage a large number of cables. The cable management assembly organizes and collects the cables in appropriate cable groups and allows the cables to swing out of the way to permit access to each equipment unit for servicing and adjustment, or for the installation or removal of an equipment unit. The cable management assemble also provides these advantages while permitting each equipment unit to slide a considerable distance out the front or back of the rack. Furthermore, the cable management system described below also limits the bend radius of the cables as each equipment unit slides in and out of the rack on its drawer slides.